1. Field of the Invention
The field of the invention is that of coherent optical sources of power with beams of variable direction.
These lasers are generally pulse lasers, the periodic operation of which makes it possible to present the intense energy desired during short periods of time.
Such sources are particularly valuable because they can be inserted into aiming systems with an external control enabling a multiple-tracking function to be carried out with a single source.
The aim of the present invention is to make a laser with control beam scanning wherein the principle of orientation of the beam is flexible in its use and easily configured.
2. Description of the Prior Art
In the field of the coherent optical sources, another patent application, filed on behalf of the same applicants, describes an assembly comprising a laser emitting a pump beam with a wavelength .lambda.p on a gas cell under pressure which, by Raman effect, emits an output beam at a Stokes wavelength (.lambda.s). A diode or, again, a laser source pumped by laser diode, emits a control beam that has the same wavelength (.lambda.s) as the output beam and is colinear with the pump beam. This enables a high-powered output signal to be obtained. A source of this type is shown in FIG. 1 and described in detail further below.
The originality of this assembly consists in the use of an external control of the Raman cell (diode, or diode-pumped laser source), enabling the making of a pulse source that is more stable in peak power, and is more reproducible from one operation to another.
In this type of source, the effective surface of the Raman wave tends to fit the profile of the surface of the pump wave. The goal pursued is to match the effective surfaces of the pump and RAMAN waves (identical surface and profile) so that the energy transferred is the maximum. In a semi-confocal type of cavity, it is possible to place the cell in an appropriate position in order to achieve this condition.
Finally, because of the external control, it is thus possible to modulate the period or, again, the emission power of the output beam. In one specific embodiment of this assembly, wherein the laser diode is replaced by a laser source pumped by laser diode, it is also possible to cause variation in the emission wavelength.
The aim of the present invention is to use this type of assembly with external control to obtain a variable orientation of the beam by means of an improvement.